Vinyl resin compositions containing factice



Patented Aug. 26, 1947 VINYL RESIN COMPOSITIONS CONTAINING FACTICE Frank S. Martin, Providence, R. I., assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey No Drawing. Application September 25, 1943 Serial No. 503,854

4 Claims. (Cl. 260-23) This invention relates to improvements in vinyl 5 resin compositions, and more particularly those relating to a certain class of vinyl ester resins.

An object of the invention is to provide vinyl chloride (Staudinger average molecular weight 24,000). These resins for the sake of brevity are hereinafter designated VYNS and VYNW, respectively. They differ in molecular weight,

resin compositions which will show improved 5 and in the percentage of vinyl chloride used in processing characteristics and better physical making the copolymer. The VYNW may be plasproperties at a reduced cost. This object is acticized and pigmented to give a coating comcomplished by theaddition of a factice to polyposition which is resistant to steam sterilization. vinyl chloride-acetate copolymer resins. Other However, the resulting composition has a very objects will be apparent from the following dehigh softening point and must be applied either scription. from solution, or, if calendered, at extremely high Compositions p p according to t e present calender temperatures. Even when applied at invention show improved resistance to steam hi h t m eratures and especially when caiendered sterilization. The composition may be calendered t 1 wer temperatures, the VYNW coating has a onto the fabric with good results at lower temtrong tendency t Shrink and crack when peratures than are normally used for calendering jected t steam sterilization, This shrinkage and similar compositions that do not contain the cracking is overcome to a marked degree by th factice- The addition of the we raises the addition of factice to the coating composition. temperature which the 9 The addition of factice further permits use of teeky- This 15 an aqvantage for apphcetmns lower calender temperatures to obtain a satiswhere the coated fabric must be folded without factory coating. VYNS is a lower molecular sticking at relatively high temperature. Also, the weight polymer and contains less vinyl chloride. addition of factice reduces the cost of the com- It may be applied at somewhat lower tempera pound. For this reason, the cost per unit volume tures than are necessary for the VYNW but the is considerably lower than that of the compounds resultant coatings are net resistant m Steam normally e The cost of course be sterilization and soften at only moderately high duced by large? amounts of cheap fillers temperatures. The addition of iactice improves such as clay or whiting; however, the addltion the VYNS composition in these respects; the 0f thgse fi ai the gg g of compositions containing factice will stick together :31? gg 1 n e compo 0 an un less when folded during steam sterilization tests The Vinyl resins can be plasticized and tThlan the compos1tions that do not contain factice.

. a e :factice contributes enough resistance to heat pounded with pigments to give compositions suitthat o t d fabri ma be h t d t F able for molding, coating, and other common aph t a i c d 6 plications for thermosetting and thermoplastic wt cu eco g so an acky at it w l resms The (mating compositions may be applied 35 stick together when folded and pressed together by calendering methods or from suitable solution. with pressure of 1 P :square inch- There are various benefits in using the factice. The effect of Z factlce enhanced by bekmg Among others, examples of vinyl acetate-vinyl the coated febne for 30 mmutes to 1 hour chloride copolymers which may be used in coating f o 240 to 280 F. The temperature and compositions, are the copolymer resins designated time O a ing may be varied as desired. as having a content of 88.5-90.5 percent vinyl The table shows t results ob by add chloride (Staudinger average molecular Weight factice to VYNS and VYNW compos io the 16,000), and a content of 93-95 percent vinyl Parts are y Weight! Table VYNS Q.

Dioctyl PhthaIate. Calcium Stearate.. White Substitute. Brown Substitute Whiting STERILIZATION TESTS Unbaked Wrinkledand Satisfactory, Very Very Slight wrinkling Film Badly Cracked Satisiactcry Satisfactory.

Blistered. Slight wrinkling. and Bllstenng. do Satisfactory Satisfactory slig l it Cracking of ....do Do.

Baked Minutes at The dioctyl phthalate serves as a plasticizer. Calcium stearate is added as a heat stabilizing agent. Whiting serves as an inorganic filler. The white substitute (white factice) is a product prepared by treating vegetable oil with sulfur chloride. The lbrown substitute (brown factice) is typical of the medium soft brown factice prepared by treating vegetable oils with sulfur. These products are representative of the general class of sulfur treated vegetable .oils sold to the rubber trade as rubber substitute. The brown substitutes in particular are made in several grades ranging from very soft materials to materials which are quite hard. The very soft factices reduce the drying up 1 the surface of the coated fabrics and the very hard types would give a stiff product. For this reason, the intermediate grades are preferable. However, the exact grade used will depend upon the properties desired for the coated fabrics.

The steam sterilization test consists of subjecting a folded sample of coated fabric to lbs. steam pressure at 121 C. for 30 minutes. The sample is removed from the sterilizer and washed with soap, water and a soft brush to remove surface finishing materials. It is then subjected to 'four additional sterilizations of minutes each at 110 C. The sample is exposed to air at least 20 minutes between each sterilization and allowed to stand in air at least 2 hours after the last sterilization before examination.

The proportion of materials used in the above examples may be varied considerably without greatly altering the results obtained. The proportion of factice used will depend on theapplication and upon the type of factice used. Normally 15 to 30 percent by weight of the factice, based on the vinyl resin, will give the desired results. In some cases, less is desirable. Compositions have been made containing as much as 50 parts of factice. However, these have such a low tensile strength that they are not suitable for most applications.

The compositions may be prepared by mixing all the dry ingredients together with the plasticizer and resins, and then thoroughly milling the mixture on a hot rubber mill until homogeneous, afterwards allowing the mix to cool, and remilling and warming for calendering, etc. Or, the factice may be dispersed alone or with a portion of the pigment and fillers in the plasticizer (by ball milling) before adding these ingredients to the vinyl compound.

The compounds disclosed in the invention may be used for coating fabrics for hospital sheeting, bags, aprons, protective clothing, gloves, and other similar articles for which fabrics coated with rubber, pyroxylin or the like has been used in the past. Compounds may also be used for molded and extruded articles. By dissolving the compounds in suitable solvents, cements for adhesives or for coating purposes may be prepared, either with or without the aforesaid mill mixing.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. An improved vinyl acetate-vinyl chloride copolymer resin composition comprising, in addition to a plasticizer for the vinyl resin, a factice in a proportion by weight of up to 30 percent, based on the vinyl resin content and eflective to increase resistance to shrinkage and cracking when the composition is subjected to steam sterlization, the said copolymer resin having from 88.5 to percent vinyl chloride content.

2. An improved vinyl acetate-vinyl chloride copolymer resin composition comprising, in addition to a plasticizer for the vinyl resin, a white factice in a proportion by weight of up to 30 percent, based on the vinyl resin content and effective to increase resistance to shrinkage and cracking when the composition is subjected to steam sterilization, the said copolymer resin having from 88.5 to 95 percent vinyl chloride content.

3. An improved vinyl acetate-vinyl chloride copolymer resin composition comprising, in addition to a plasticizer for the vinyl resin, a brown factice in a proportion by weight of up to 30 percent, based on the vinyl resin content and effective to increase resistance to shrinkage and cracking when the composition is subjected to steam sterilization, the said copolymer resin having from 88.5 to 95 percent vinyl chloride content.

4. A fabric coated with an improved resin composition as set forth in claim 1.

FRANK S. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,275,376 Ellis Mar. 3, 1942 2,111,006 Robie Mar. 15, 1938 OTHER REFERENCES Page 199, Summary of Current Literature, Abstracts-Research Assn. of Br. Rubber Mfrs., vol. 22, No. 6, June 1944.

Vinylite Resins-Their Forms, Properties, and Uses, p. 7 pub. 1942 by Carbide and Carbon Chem. Corp., N. Y. 

